Diatom Test Slide version 2.0

A) This test microscope slide contains 5 cleaned, selected and micromanipulated Diatom species with striae, areolae and poroids that can be RESOLVED or DETECTED through a light microscope. The resolving power of a microscope is measured by its ability to differentiate two lines or points in an object.This test microscope slide can be also used as a TRAINING TOOL or a TEACHING TOOL, for example it is extremely useful to- practice using your microscopes at their highest levels- examine the variations in contrast and resolution by regulating the condenser aperture diaphragm- understand the importance of correction collar for minimazing spherical aberration- examine the variations in resolution by using different wavelengths of light

B) This is a STANDARDIZED TEST, in fact each microscope slide has the same production characteristics: - In order to give you the best conditions for resolution and contrast, Diatoms are attached / fixed to the UNDERSIDE of a properly thick cover glass (and not commonly on the microscope slide!), so there is no space between Diatom frustules and cover glass (although this procedure requires several special manufacturing precautions). Furthermore, the mounting to the underside of the cover glass allows to easily use all oil immersion objectives (even those with very short working distance, such as plan-apochromat 63x/1,4 or 100x/1,4);- The MICROFILTERED MOUNTANT (DIATOM CUBED, produced in Diatom Lab) has a high refractive index (greater than 1.7) and belongs to the same production lot;- The customized cover glass with HIGH OPTICAL QUALITYhas been manufactured in Germany specifically for Diatom Lab;-Each Diatom species belongs to a sample collected in the same place / depth / time

C) This product has been thoroughly tested before going to market, using dry, oil immersion and double immersion light microscopy (also the last two Diatom species have been tested on Zeiss Axio Imager.A2 research microscope using the Zeiss Achromatic-aplanatic condenser 1,4 H D Ph DIC, the Zeiss Objective 63x/1,4 Oil DIC ∞/0,17 M27 and other high aperture (N.A. 1,3 and 1.4) Zeiss M27 objectives) TECHNICAL SUGGESTIONS:

Diatom number 4 Species: Navicula oblonga (Kützing) KützingDetails to detect: areolae (lineolae), forming the striae Areolae (lineolae) in 10 µm: 48-50, see Scanning Electron Microscope (SEM) measurements in the photo galleryAVERAGE DISTANCE BETWEEN areolae (lineolae): 0,14 µm, see Scanning Electron Microscope (SEM) measurements in the photo galleryThe theoretical limit of resolution of most light microscopes is ~ 0.2 μm, but these areolae (lineolae) can be detected by the techniques below, thanks to Diatom Cubed high refractive index mountant!Recommended microscope objectives: oil-immersion 63 or 100x objectives having a good or excellent numerical aperture (starting from 1,2; better: 1,3 or 1,4) Suggested techniques: Double immersion = Oil immersion objective and Oil immersion condenser and:Polarized light (the polarizers should be oriented perpendicular to each other = maximum level of extinction);or Circular oblique illumination (C.O.L.) with polarized light;orDark field illumination using an immersion dark field condenser (better 1,2/1,4);or Differential interference contrast (DIC);or UV illumination: in this case highly specialized laboratory facilities are required (it is dangerous for the eyes, it requires the use of special protection devices, accessories and cameras. Please refer to the operating manual of your instruments);or some variants of the Differential interference contrast (such as AVEC-DIC, the Allen Video-enhanced Contrast);or IRC (Interference reflection contrast technique)

Diatom number 5Species: Pinnularia nobilis (Ehrenberg) EhrenbergDetails to detect:PoroidsAVERAGE DISTANCE BETWEEN POROIDS: 0,11 µm (NEW MORE DIFFICULT SAMPLE!), see Scanning Electron Microscope (SEM) measurements in the photo galleryAgain, the theoretical limit of resolution of most light microscopes is ~ 0.2 μm, but these poroids can be detected by the techniques below, thanks to Diatom Cubed high refractive index mountant!Recommended microscope objectives: oil-immersion 63 or 100x objectives having a very good or excellent numerical aperture (1,3 or 1,4) Suggested techniques: Double immersion = Oil immersion objective and Oil immersion condenser and:Polarized light (the polarizers should be oriented perpendicular to each other = maximum level of extinction) with possibly oblique illumination;or Immersion dark field condenser (better 1,2/1,4) with Polarized light (the polarizers should be oriented perpendicular to each other = maximum level of extinction)